Assisted
by a coworker in the Molecular Desorption and Analysis Laboratory,
George Aldrich, left, takes a scientific whiff.

George
Aldrich,
White Sands Test Facility,
Las Cruces, New Mexico

NASA's
Nose: Avoiding smelly situations in space

April 2003
-- Thanks to George Aldrich and his team of NASA sniffers, astronauts
can breathe a little bit easier. Aldrich is a chemical specialist
or “chief sniffer” at the White Sands Test Facility’s Molecular
Desorption and Analysis Laboratory in New Mexico. His job is to
smell items before they can be flown in the space shuttle.

Aldrich explained
that smells change in space and that once astronauts are up there,
they’re stuck with whatever smells are onboard with them. In space,
astronauts aren’t able to open the window for extra ventilation,
Aldrich said. He also said that it is important not to introduce
substances that will change the delicate balance of the climate
of the International Space Station and the space shuttle.

More than being
merely unpleasant, smells in space can indicate a health threat.
Even objects that give off no odor can emit dangerous chemicals
by a process called off-gassing. If an object’s off-gassing has
toxic effects, it can be a matter of life and death.

“Smell is brought
out by confined spaces and heat,” said Aldrich, “yet astronauts
have no way of escaping a smell if it becomes pervasive. If that
smell comes from dangerous compounds, it’s a serious health threat.”

It is Aldrich’s
job to use his sense of smell to ensure the olfactory
comfort, as well as the safety, of astronauts on orbit.

When he was
just 18 years old, Aldrich began working at White Sand's fire department
and was asked to be on the department’s Odor Panel. Aldrich explained
that one of the requirements to get a job as a sniffer is a lack
of any allergies or respiratory problems. “If
you have a lot of allergies, your nasal passages are already irritated
and cannot be used,” he said.

NASA calibrates
and certifies its sniffers’ noses every four months using a “10-bottle
test” in which seven of the bottles have odors and three of them
are blanks. The seven scents must be categorized as musky, floral,
ethereal, camphoraceous, minty, pungent or putrid.

According to
the NASAexplores Web site,
Aldrich’s team tests nearly all items that astronauts would encounter
during their flight -- including fabric, toothpaste, circuit boards,
makeup and even the ink on their checklists.

First, the
items are tested for toxicity. They are placed into individually
sealed containers and then into an oven, which is heated to 49 degrees
Celsius (120 degrees Fahrenheit) for three days to speed up the
off-gassing process. The gases are then extracted and tested to
determine whether they are toxic or carcinogenic. If the gases are
deemed safe, the items then undergo odor testing.

Aldrich and
four other team members smell the items and rank them on a scale
of zero to four, ranging from non-detectable (zero), to barely detectable,
easily detectable, objectionable and offensive (four). Aldrich refers
to level four as “get-me-out-of-here.” Because the sense of smell
can vary from person to person, sniffers give each object its own
ratings, from which an average is obtained. If an item rates more
than a 2.4 on the scale, it fails the test and is not allowed on
the flight. Some items that have failed are camera film, felt-tipped
markers, mascara and certain types of stuffed animals. Aldrich has
done 765 of these “smell missions” to date.

NASA could
use dogs or “electronic noses” for this testing, but as Aldrich
pointed out, the Agency would rather use human sniffers because
they serve as a screening test for the also-human astronauts. The
human testers can more accurately identify smells that will offend
the human crewmembers than an electronic nose could.

As a result
of his career, Aldrich has had some uncommon opportunities. He has
served as a judge four times at the Odor-Eaters Rotten Sneaker Competition.
He has also appeared on television a number of times, including
appearances on two game shows.

While others
may chuckle at his unusual occupation, Aldrich said he believes
in its value.